SQLAlchemy ORM – Eager Loading Eager load reduces the number of queries. SQLAlchemy offers eager loading functions invoked via query options which give additional instructions to the Query. These options determine how to load various attributes via the Query.options() method. Subquery Load We want that Customer.invoices should load eagerly. The orm.subqueryload() option gives a second […]
Category Archives: sqlalchemy
SQLAlchemy Core – Using Conjunctions Conjunctions are functions in SQLAlchemy module that implement relational operators used in WHERE clause of SQL expressions. The operators AND, OR, NOT, etc., are used to form a compound expression combining two individual logical expressions. A simple example of using AND in SELECT statement is as follows − SELECT * […]
SQLAlchemy Core – Using Set Operations In the last chapter, we have learnt about various functions such as max(), min(), count(), etc., here, we will learn about set operations and their uses. Set operations such as UNION and INTERSECT are supported by standard SQL and most of its dialect. SQLAlchemy implements them with the help […]